Synthetic polyesters now used as absorbable ligatures can be extruded into yarns and woven into a seamless tubular fabric. When exposed to the proteases and esterases found in body fluids, such structures undergo biological decay and therefore can be considered for resorbable vascular prostheses. Other homo- and copolyesters which we have synthesized from Krebs-cycle dicarboxylic acids provide a broad range of in vivo resorption times which allow different degrees of tissue ingrowth and collagen deposition in a vascular implant before complete disappearance of the synthetic scaffold. These new polymers can be coated onto custom-made bioresorbable vascular prostheses to modify their initial surface and bulk properties, their reactivity with tissues, and the rate of invasion of live cells. The goal of this program is to explore the concept of in-situ vascular reconstruction in and around a synthetic bioresorbable fabric, and to study the process whereby the yarns disappear while promoting the reorganization of tissues. This three year project includes the fabrication of woven vascular grafts made of polyglycolic acid yarns; the synthesis and evaluation of new polyesters to serve as coatings for the prosthesis so as to retard the rate of yarn resorption in vivo; paired carotid implantations in sheep and dogs with graft retrieval after various periods; and evaluation of explants by a range of mechanical tests and chemical and histological studies in order to correlate polymer decay with cell ingrowth over time.